drivers/mmc/host/of_mmc_spi.c

   1 /*
   2  * OpenFirmware bindings for the MMC-over-SPI driver
   3  *
   4  * Copyright (c) MontaVista Software, Inc. 2008.
   5  *
   6  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/slab.h>
  18 #include <linux/irq.h>
  19 #include <linux/of.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/spi/spi.h>
  22 #include <linux/spi/mmc_spi.h>
  23 #include <linux/mmc/core.h>
  24 #include <linux/mmc/host.h>
  25
  26 /* For archs that don't support NO_IRQ (such as mips), provide a dummy value */
  27 #ifndef NO_IRQ
  28 #define NO_IRQ 0
  29 #endif
  30
  31 MODULE_LICENSE("GPL");
  32
  33 struct of_mmc_spi {
  34         int detect_irq;
  35         struct mmc_spi_platform_data pdata;
  36 };
  37
  38 static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
  39 {
  40         return container_of(dev->platform_data, struct of_mmc_spi, pdata);
  41 }
  42
  43 static int of_mmc_spi_init(struct device *dev,
  44                            irqreturn_t (*irqhandler)(int, void *), void *mmc)
  45 {
  46         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
  47
  48         return request_threaded_irq(oms->detect_irq, NULL, irqhandler,
  49                                         IRQF_ONESHOT, dev_name(dev), mmc);
  50 }
  51
  52 static void of_mmc_spi_exit(struct device *dev, void *mmc)
  53 {
  54         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
  55
  56         free_irq(oms->detect_irq, mmc);
  57 }
  58
  59 struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
  60 {
  61         struct device *dev = &spi->dev;
  62         struct device_node *np = dev->of_node;
  63         struct of_mmc_spi *oms;
  64         const __be32 *voltage_ranges;
  65         int num_ranges;
  66         int i;
  67
  68         if (dev->platform_data || !np)
  69                 return dev->platform_data;
  70
  71         oms = kzalloc(sizeof(*oms), GFP_KERNEL);
  72         if (!oms)
  73                 return NULL;
  74
  75         voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
  76         num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
  77         if (!voltage_ranges || !num_ranges) {
  78                 dev_err(dev, "OF: voltage-ranges unspecified\n");
  79                 goto err_ocr;
  80         }
  81
  82         for (i = 0; i < num_ranges; i++) {
  83                 const int j = i * 2;
  84                 u32 mask;
  85
  86                 mask = mmc_vddrange_to_ocrmask(be32_to_cpu(voltage_ranges[j]),
  87                                                be32_to_cpu(voltage_ranges[j + 1]));
  88                 if (!mask) {
  89                         dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
  90                         goto err_ocr;
  91                 }
  92                 oms->pdata.ocr_mask |= mask;
  93         }
  94
  95         oms->detect_irq = irq_of_parse_and_map(np, 0);
  96         if (oms->detect_irq != 0) {
  97                 oms->pdata.init = of_mmc_spi_init;
  98                 oms->pdata.exit = of_mmc_spi_exit;
  99         } else {
 100                 oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
 101         }
 102
 103         dev->platform_data = &oms->pdata;
 104         return dev->platform_data;
 105 err_ocr:
 106         kfree(oms);
 107         return NULL;
 108 }
 109 EXPORT_SYMBOL(mmc_spi_get_pdata);
 110
 111 void mmc_spi_put_pdata(struct spi_device *spi)
 112 {
 113         struct device *dev = &spi->dev;
 114         struct device_node *np = dev->of_node;
 115         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
 116
 117         if (!dev->platform_data || !np)
 118                 return;
 119
 120         kfree(oms);
 121         dev->platform_data = NULL;
 122 }
 123 EXPORT_SYMBOL(mmc_spi_put_pdata);